获取相机预览帧，调用相机拍照

package com.example.sj.mycamera;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.ImageView;

import java.io.IOException;
import java.util.List;

public class MainActivity extends Activity implements SurfaceHolder.Callback, Camera.PictureCallback {
    Camera mCamera;
    SurfaceView mSurfaceView;
    SurfaceHolder mSurfaceHolder;
    private int mCurrentPos = 0;
    ImageView mImageView;
    boolean hasAutoFocus=false;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }
    
    private void initView() {
        mImageView= (ImageView) this.findViewById(R.id.imgv);
        mSurfaceView = (SurfaceView) this.findViewById(R.id.sv);
        mSurfaceHolder = mSurfaceView.getHolder();
        //2.+
        //mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        mSurfaceHolder.addCallback(this);
    }
    
    private void startPreView() {
        int numberOfCameras = Camera.getNumberOfCameras();
        System.out.println("numberOfCameras = " + numberOfCameras);
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        
        for (int i = 0; i < numberOfCameras; i++) {
            //把指定索引位置摄像头信息封装到cameraInfo对象中
            Camera.getCameraInfo(i, cameraInfo);
            if (i==mCurrentPos&&cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
                mCamera=Camera.open(i);
            }
            
            if (i==mCurrentPos&&cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                System.out.println("i--->"+i);
                mCamera=Camera.open(i);
            }
        }
        mCamera.setDisplayOrientation(getCameraDegrees());
        Camera.Parameters parameters = mCamera.getParameters();
        //获取全部的预览尺寸
        List supportedPreviewSizes = parameters.getSupportedPreviewSizes();
        System.out.println("预览尺寸列表：");
        for (Camera.Size size : supportedPreviewSizes) {
            System.out.println("宽： " + size.width + "   高： " + size.height);
            if (size.width*1.0f/size.height==16*1.0f/9){
                Log.e("xx", "预览选择：---》"+size.width+"　"+size.height );
                parameters.setPreviewSize(size.width, size.height);
                break;
            }
        }
        System.out.println("预览尺寸列表完毕");
        //获取全部最终成相尺寸
        List supportedPictureSizes = parameters.getSupportedPictureSizes();
        System.out.println("最终成相尺寸列表：");
        for (Camera.Size size : supportedPictureSizes) {
            System.out.println("宽： " + size.width + "   高： " + size.height);
            if (size.width*1.0f/size.height==16*1.0f/9){
                Log.e("xx", "最终成相选择：---》"+size.width+"　"+size.height );
                parameters.setPictureSize(size.width, size.height);
                break;
            }
        }
        System.out.println("最终成相尺寸列表完毕");
        
    
        if (mCurrentPos == 0) {
            parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
            parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
            
        }
        mCamera.setParameters(parameters);
        try {
            mCamera.setPreviewDisplay(mSurfaceHolder);
        } catch (IOException e) {
            e.printStackTrace();
        }
        mCamera.startPreview();
        
        
    }
    
    public int getCameraDegrees() {
        int degress = 0;
        switch (this.getWindowManager().getDefaultDisplay().getRotation()) {
            case Surface.ROTATION_0:
                degress = 90;
                break;
            case Surface.ROTATION_90:
                degress = 0;
                break;
            case Surface.ROTATION_180:
                degress = 270;
                break;
            case Surface.ROTATION_270:
                degress = 180;
                break;
        }
        
        
        return degress;
    }
    
    
    public void resetCamara() {
        if (mCamera == null) {
            return;
            
        }
        mCamera.stopPreview();
        mCamera.release();
    }
    
    public void 切换(View v) {
        resetCamara();
        if (mCurrentPos == 0) {
            mCurrentPos = 1;
            
        } else {
            mCurrentPos = 0;
        }
        startPreView();
    }
    
    
    public void 拍照(View v) {
        hasAutoFocus=false;
        if (mCurrentPos==1){
            mCamera.takePicture(null,null,this);
            
        }else {
            try {
                mCamera.autoFocus(new Camera.AutoFocusCallback() {
                    @Override
                    public void onAutoFocus(boolean success, Camera camera) {
                        //自动对焦成功，只执行一次拍摄
                        if (!hasAutoFocus){
                            hasAutoFocus=true;
                            mCamera.takePicture(null,null,MainActivity.this);
                        }
                    }
                });
            } catch (Exception e) {
                mCamera.takePicture(null,null,MainActivity.this);
            }
        }
    }
    public void 重拍(View v){
       
        mImageView.setVisibility(View.GONE);
        startPreView();
    }
    
    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        //初次创建---第一次能看见
        startPreView();
    }
    
    
    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        //状态变化
    }
    
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        //最终销毁---看不见了
        resetCamara();
    }
    
    
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        resetCamara();
        Bitmap bitmapOrigin= BitmapFactory.decodeByteArray(data,0,data.length);
        Matrix matrix=new Matrix();
        if (mCurrentPos==0){
            matrix.postRotate(90);
    
        }else {
            matrix.postRotate(-90);
            matrix.postScale(-1, 1);
    
        }
        Bitmap bitmapUse=Bitmap.createBitmap(bitmapOrigin,0,0,bitmapOrigin.getWidth(),bitmapOrigin.getHeight(),matrix,false);
        mImageView.setImageBitmap(bitmapUse);
        mImageView.setVisibility(View.VISIBLE);
        
        
    }
}

activity_main

    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.sj.mycamera.MainActivity">

            android:id="@+id/sv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />
    
            android:id="@+id/imgv"
        android:visibility="gone"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
            android:text="切换"
        android:onClick="切换"
        android:layout_alignParentBottom="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
            android:text="X"
        android:onClick="重拍"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

            android:text="拍照"
        android:onClick="拍照"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>